It has all the challenges of Three Mile Island plus there are four damaged reactors not just one
By Dan Yurman
The effort to contain the nuclear reactor crisis at Fukushima brings to mind the 1933 horror movie King Kong, in which a giant ape, escaped from captivity, and perched at the top of the Empire State Building, is fatally wounded by a swarm of war planes of the era.
King Kong - image source Wikipedia
While fictional film character Carl Denham intones his famous last line “It was beauty killed the beast,” a less prosaic New York sanitation department might have been wondering how to remove a giant dead gorilla carcass from the corner of 5th Ave. and 34th St.
Kong’s fall would have created a cleanup problem of immense scale. It would have been “beyond the design basis” of even the entire fleet of city garbage trucks.
Six gorillas at Fukushima
This dramatic movie metaphor is relevant as a visual image of the scope of the problem faced by Tokyo Electric Power Corp. (TEPCO) with the eventual decommissioning of six reactors at Fukushima. The utility doesn’t have just one dead giant gorilla, there are six. The first three nuclear reactors are likely to be found to be fatally compromised with heat damaged fuel assemblies from loss of cooling water. Partial melting of fuel may be part of the problem.
Massive hydrogen explosions blew the roofs off of secondary containment structures at reactors 1, 3, and 4. The fourth reactor is also likely severely damaged beyond repair. Its spent fuel pool is exposed to the open air as a result of one of the huge hydrogen explosions.
The fifth and sixth reactors, relatively undamaged, may never restart because of wrecked balance of plant infrastructure and ferocious public opposition which is leveraged by Japanese law that gives veto power over nuclear facilities to the provincial government.
BWR reactor schematic. Image from World Nuclear Association
The 15-meter high tsunami swept away the normal infrastructure of a nuclear power station which, along with rubble from the hydrogen explosions, put debris across access roads and rail sidings blocking delivery of emergency equipment. Efforts to control leaks from buildings and trenches may go on for months or years. In short, it will be a very dangerous place to conduct cleanup work.
Precedent from Three Mile Island
The precedent TEPCO will have to rely on is the cleanup of the Three Mile Island (TMI) accident in the U.S. The cleanup of the badly damaged reactor at Three Mile Island, which began in 1979, took more than a decade ending in 1993. TEPCO’s timeline may be much longer.
The New York Times reported that the first major phase of the TMI cleanup was completed in April 1990, when workers finished shipping 150 tons of radioactive wreckage from the damaged reactor vessel to Idaho for storage. According to a history of the Idaho lab’s involvement in the project, 49 casks containing reactor fuel debris were transported by rail through 10 states in 22 shipments. Cleanup at that point had cost over $1 billion.
TMI cask on US Hwy 20 near INL. Image courtesy Idaho National Laboratory
There are significant differences between the situation at TMI and Fukushima. The biggest and most dangerous differences are the extent of uncontrolled radioactive contamination outside the reactors at the plant site.
A second cleanup challenge, unlike the TMI experience, is that the surrounding countryside in Japan is like a war zone with lack of access by road and rail, power lines are down, and potable water, food, and housing are all in very short supply.
There some immediate steps TEPCO needs to take to start the cleanup process at Fukushima. It must get most of the radioactive water off the site and control what remains. It needs to control radioactive debris from the hydrogen explosions. Most importantly, it must find a path to remove the fuel from the damaged reactors or execute a plan to store it in place indefinitely.
Drying out the Fukushima reactor site
The removal of huge volumes of radioactive water from the site is the first priority. The Japanese have been pouring uncounted tons/day of water on four reactors since mid-March. Headlines in the news media on April 5 report TEPCO needs to remove 11,500 metric tonnes of water from the plant.
The Wall Street Journal reported April 5 that TEPCO was discharging 4,800 (short) tons/day of radioactive water directly into the ocean. That would be 96,000pounds or about 11,500 gallons of water. TEPCO characterized the radioactivity level of the discharge as “low.”
Fukushima reactor complex prior to March 11, 2011
According to the WSJ, authorities said about 20,000 tons of radioactive seawater still remain in the turbine building and the cable trench of each of reactors Nos. 1-3, for a total of 60,000 tons. That’s 120 million pounds of water or 14,370,000 gallons of water. (1 gallon of water weighs 8.35 pounds)
Readers should be aware that the western press has had numerous difficulties with translations of Japanese language reports of reactor status information. Mistakes and errors by TEPCO, as well as wholesale retractions, have created problems for almost all numerical references from the utility subjecting them to continuous second guessing and review.
Anyway you count it, there is a lot of water and no way to store or dispose of it on the site. The option exists for TEPCO is to run a pipeline several miles out to sea from the reactor site and pump the water out there.
According to a BBC report for April 4, 2011, the Kuroshio Current is the North Pacific equivalent of the Gulf Stream in the Atlantic. It hugs the Asian continental slope until about 35 degrees North, where it is deflected due east into the deep ocean as the Kuroshio Extension.
Experts interviewed by the BBC say this means pollutants in its grasp, such as radioactive water from Fukushima, will tend over time to be driven out into the middle of the Pacific where they will become well mixed and diluted over time.
There will likely be heated political objections to this scenario, but TEPCO is more or less out of land-based options. It needs to get the radioactive water out of the plant if it has any chance to make progress with gaining control of even more dangerous radioactive contamination throughout the entire reactor complex including spent fuel in Unit 4 and damaged fuel in Units 1-3.
Securing the site
Next, the site needs to be washed down to remove surface radioactive contamination. Yes, this will produce more radioactive water, but it’s better to send it out to sea than to leave it in place to harm site workers.
Also, according to an April 6 New York Times report, radioactive particles from the spent fuel pool for unit 4 may have been blown as much as a mile away by the hydrogen explosion. These materials need to be found and removed to a safe interim disposal area.
Fukushima reactor complex after hydrogen explosions at reactors 1, 2 & 4
Fukushima reactor units 1-4 could to be covered by an semi-rigid, inflatable tent the size of a football stadium. This structure, supported by a light steel framework and constant air pressure blown into it, would protect the damaged reactors and cleanup workers from the elements. While a typhoon or other extreme weather could damage the air supported structure, it is easier, quicker, and less costly, to rebuild one than to try to encase all four reactors in a giant concrete shell.
None of this site preparation work can take place until the reactors themselves are in a state of cold shutdown. This may be accomplished through restoration of electrical power and control of the reactor cooling systems. If the cooling systems are damaged, and don’t work, TEPCO will have to come up with a system that does the job which will likely continue producing hundreds of tons a day of radioactive wastewater.
It could be some time, perhaps as long as several years, before remote controlled, radiation hardened robots can be sent into the reactor cores at Units 1-3 to take a look at damage there. The reason is the wreckage of the damaged secondary containment structures at reactor units 1 & 2 will have to be removed so a work crew and their gear can be staged to access the primary containment structure. Unit 3, which has a relatively intact secondary containment structure, could be the first reactor to give up its secrets.
According to a Wall Street Journal interview April 2 with veterans of the cleanup at TMI, heat damaged fuel elements will be difficult to extract from the reactor pressure vessels especially if temperatures were high enough to melt the zirconium cladding that hold the fuel elements in place. Once that happens, fuel pellets fall to the floor of the reactor pressure vessel.
If the any of the fuel itself is melted, TEPCO might opt to wait for years with a buttoned up reactor pressure vessel and secure primary containment structure for everything to cool down through natural attenuation of residual heat and the cycle of radioactive half lives. Eventually, like TMI, the fuel from the reactors and spent fuel pools could be transferred to permanent dry cask storage.
TMI fuel metl down - Image courtesy Idaho National Laboratory
If TEPCO can’t find safe technical path forward to this solution, then an alternative is to eventually entomb the reactor pressure vessels in place by pouring concrete into the primary containment structures for units 1-3, and the spent fuel pool in unit 4. This solution may be forced on TEPCO if it finds that any of the primary containment structures are damaged from the original earthquake or by aftershocks.
According to a Bloomberg news report for March 30, the government hasn’t ruled out sealing the plants 1-4 in concrete says Chief Cabinet Secretary Yukio Edano. Though he didn’t mention it, one of the issues the government will need to evaluate is whether the primary containment structures could safely hold all that concrete. That weight could put new stressed on the structures.
Cost of cleanup
TEPCO’s long-term cleanup costs could be in the tens of billions and take decades to complete. This activity alone could turn the utility into a semi-permanent ward of the state unless cleanup, and liabilities, are taken over entirely by the government through some form of receivership for the reactor site.
Fukushima could remain a no man’s land for decades given the huge, almost unimaginable costs of cleanup. The government will likely look to find reasons to stretch out cleanup for financial reasons regardless of domestic and international pressure. Japan’s government is carrying a huge debt load as it is.
The complexity of performing the decommissioning of six reactors four of which are severely damaged and in an unknown condition will drive up costs at every turn. The last time Japan decommissioned a reactor, which was a clean site, it took the government more than two decades to complete the job.
By comparison, the decommission of the Zion nuclear power plant in Illinois, which is well controlled under regulatory scrutiny from the NRC, is expected to cost $900 million and take a decade to complete. A New York Times report for November 22, 2010, noted it cost Exelon $10 million a year just to “baby sit” the plant in cold shutdown status.
Zion nuclear power station in Illinois awaiting decommissioning
The plant will be chopped up into pieces and shipped to a special landfill in Utah that can receive solid radioactive waste. There will be no separation of radioactive and non-radioactive materials. Everything will be assumed to be radioactive and will go to one disposal site.
Where to put radioactive waste?
This raises a key question for Japan. Where will it dispose of radioactive debris from Fukushima? It can’t leave the material at the seashore to perpetually contaminate the cities and farms in the surrounding countryside and pollute highly productive fishing waters.
The Kyodo News wire service reported April 5 that the Japanese government is studying the possibility of borrowing a Japan-funded radioactive waste disposal facility from Russia to help contain radioactive water.
“We are checking whether it is technically possible to use the facility for this current event, and whether the facility’s machines are working smoothly,” Hidehiko Nishiyama, a spokesman for the government’s Nuclear and Industrial Safety Agency, told a press conference.
Suzuran - At this time, it is moored opposite Vladivostok's shores at the Zvezda Shipyard in Bolshoy Kamen Bay.
He also said Japan has been communicating with Russia about using a floating facility, called Suzuran, (right) which Japan gave to Russia in 2001 to help dispose of low-level radioactive liquid waste from decommissioned nuclear-powered submarines.
Japan gave the facility to Russia as environmental concerns were raised after Russia dumped radioactive waste into the Sea of Japan in 1993 in the process of dismantling its nuclear subs.
There is even less certainty for high level waste and other solid radioactive debris (RH-TRU) which cannot be contact handled in the near term. Ten years ago, Japan created the Nuclear Waste Management Organization of Japan (NUMO) which was established under the jurisdiction of the Ministry of Economy, Trade and Industry.
NUMO is responsible for selecting a permanent deep geologic repository site, construction, operation and closure of the facility for waste emplacement by 2040. Site selection was begun in 2002.
Final selection of a repository location is expected by 2027. Japan may have to speed up the site selection process once it gets serious about the decommissioning of the six reactors at Fukushima. A 2008 briefing shows a lot of process work but not much progress in selecting much less building a geologic repository for high level waste. There’s a long way to go.
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Dan Yurman publishes Idaho Samizdat, a blog about nuclear energy. He is a frequent contributor to the ANS Nuclear Café.
ANS Nuclear Cafe 
There are (or were) excellent heat exchange systems right on site. The primary heat pathway goes from steam lines through to the condenser wetwell, and back to the reactor. The secondary side carries clean seawater. This all requires pumping power in both loops, of course.
Could this closed-loop system be “cobbled up” to serve as a heat removal system, and possibly (with modifications) as a water decontamination system?
Just a thought, for consideration by the author.
No one has been inside reactor units 1-3. This means the condition of the primary pumps are unknown. If the pumps are underwater, or especially if they have been exposed to sea water, their motors may need repair.
Dan: The pumps that would need power are the condenser cooling water pumps and the feedwater pumps. Recirc pumps would not be involved.
Repairing pumps is not easy, I agree — but relative to other options this may well look easier.
Dan
Dan – very interesting article. As a retired professional mariner, however, I have to point out that you seem to be overlooking the obvious advantage that TEPCO has compared to GPU with regard to arranging shipments of its debris. The ocean front site gives Fukushima access to the world’s most amazing “highway” for transporting large objects. There is no need for a lot of local infrastructure or for obtaining permission from local jurisdictions. Build a pier, load up some ships and start moving.
Overall, TEPCO is focused on emergency response. The utility isn’t thinking yet about long term D&D.
I think a key issue to answer your questions about responses to disposal of water is how much water is there at Fukushima? The answer to this question determines what range of short-and-long term solutions are feasible.
The amount of water going into the plant is enormous and all of it acquires some amount of radioactive contamination. A ton of water at 8.35 pounds per U.S. gallon of water works out to 2000 / 8.35 = 240 gallons. TEPCO is pouring 200 tons / day of water into each reactor (48,000 gallons). Four reactors are getting the emergency water so 800 tons / day would be equal to 192,000 gallons / day.
We know that TEPCO has been using first sea water and then later fresh water continuously for this purpose since March 16. It is now April 7. So in 21 days the amount of water we know about that has been added to the plant is [21 days] * [192.000 gal / day or over 4 million gallons.
This is water we know about. We don’t have an account of how much water was left behind by the tsunami in pits, trenches, and other underground structures. We don’t know how much water has been added since March 11 by rainfall and melting snow.
We don’t know how much water, or its level of radioactive contamination, is also in pits, trenches, and other structures having leaked from turbine buildings and piping to the reactor. As these are BWR reactors, there is no secondary loop. The steam from the reactor pressure vessel goes right to the turbine building. In an emergency shutdown, all valves between the reactor pressure vessel and the turbine building are supposed to close immediately.
TEPCO thinks these valves and pipes are broken and may be one of many sources of leaks of radioactive water. The fact that the “leak” from the cable trench has been stopped only means the point of discharge has been closed up. The radioactive water is still on site.
Earlier this week TEPCO said it would discharge 11,500 metric tonnes of contaminated water into the sea. A metric ton is 2,200 pounds or 264 gallons. The math is [264 gal/ton] * [11,500] = 3 million gallons. This is a million gallons, or 25%, short of the 4 million gallon estimate derived above. It means that either TEPCO doesn’t have it due to evaporation, or run off into the sea, or doesn’t know where it went. All these pathways are plausible in terms of accounting for loss.
The evaporation of radioactive water from the reactors is carrying any water soluble radioactive isotopes with its. Transport by air could take it anywhere which may be one reason I-131 has been found in crop leaves in Fukushima.
The good news for TEPCO is that running a pipeline from the plant about ten miles out to sea would provide for effective short term disposal of low levels of contamination. Fishing would have to be banned in the area. The radioactive iodine would degrade in a few weeks. Radioactive cesium would be subject to bioaccumulation in fish bones.
Another solution is to get some barges, fill them daily, and start a train of the barges being towed 100 miles out to sea so that prevailing current that runs along the continental shelf pulls the radioactivity into the center of the Pacific where it will dilute and harm no one. The Fukushima site has docks and could implement this solution quickly. The barges would have to be disposed of at sea beyond the continental shelf when the crisis was over.
Longer term in addition to the suggestion you provided, bringing portable boilers to the site, heating the water to steam, running it through filters, or capturing residuals at the bottom of the boiler, would make for a quick solution. I’m not familiar with the effectiveness of demineralizers in removing radioactivity from water so I can’t comment on it.
All of these ideas are focused on a single principle which is getting the water off site or separating and reducing the radioactive residuals in it to a much smaller and manageable volume.
I hope this brief review is helpful. I don’t want it to be seen as a technical analysis since it really is just back of the envelope thinking.
It is standard practise to decontaminate water with fission products using resin and other filters. They can keep circulating water for months, leaching out the damaged fuel rods, and cleaning up the water in a temporary cleanup unit onsite. During normal operation, sometimes fuel rods fail and there is a filter system that removes fission products. This is done all the time. Its also a very effective way to make landfills inert; just keep percolating water and clean that up, at some point nothing much will leach out and you can leave it with minimal case, as if it was just sand and rock.
Removing positive ions and negative ions is done by seperate filters, also there can be active carbon filters that remove more neutral stuff. Water treatment technology is well advanced and these days we can clean water from any contamination highly effectively.
TMI cost about 1 billion to cleanup so we’re looking at at least 4 billion. Given likely increased damage and some remediation (I believe quite limited based on radiation measurements nearby) which costs money. 5 to 10 billion USD maybe, its highly speculative at this point.
Good Morning,
Having never seen the plant’s full P&IDs, it is not clear to me whether they can repair the existing piping systems or whether they will need to build a new water circulation /core cooling / decontamination closed loop system with some tie-in to the existing reactor piping.
I think a higher priority task is building a system to capture and treat the waste water for the present cooling “system”.
Can they make good estimates on how much steam is being generated? I assume they are measuring the water full into the system. From those two numbers, you could determine whether there is significant leakage.
The nitrogen injection opened my eyes to the fact that hydrogen is still being formed and I have heard this being attributed to split water molecules due to heat. But this could be from the zirc/steam reactions too, right?
Finally how the heck did the number 4 reactor pool go uncovered? That to me is the one true human error. They had the tools to prevent that one. Reactors 1 through 3 seem to have occur because the Management was slow to “pull the trigger” on the seawater procedure.
In the US, is the process for making the decision to implement those types of highly expensive options fully defined or would the planter operator be on the phone to the CEO asking permission?
Thanks all. All this stuff makes me wish I had been accepted in to the nuke program out of school [had the grades, fluked the hearing test].
Tom Murphy
I have what may be a stupid question.
My understanding is that they’re pumping clean water into the reactors, contaminated water is coming out, and that is the source of much (most?) of the contaminated water that now has to be dealt with.
The (stupid?) question is, why don’t they just pump the contaminated water back into the reactors? Presumably, the fresh water they’re pumping in comes from some source. Just use the large bodies of contaminated water that’s piling up as the source instead. I know this would require shielding the pumps and the reactor injection lines, but still…
I also believe that resin filtering should definitely be set up at some point, but that isn’t necessary for, or related to, the option of pumping the dirty water back into the reactors.
Does anyone know what’s stopping them from doing this? Why must clean water be pumped into the reactors?
I’m pretty sure that when they finally do get the primary pumping systems back on line, the result would be a closed water loop that contains very contaminated water (i.e., dirty water will be pumped back into the reactor). There’s no reason the same thing can’t be (effectively) set up with the external (portable) pumping system they now have.
In answer to Jim Hopf, I don’t know what TEPCO is doing about capturing waste water from the cooling stream being sprayed on the spent fuel pool at Unit 4 and on Units 1-3. Here are some initial thoughts about where it is going after it hits the reactors.
There is evidence from photographs that there is some loss to evaporation based on steam plumes from Units 2 & 4. A worst case is that the water cascades to the ground running into storm drains and on to work surfaces at ground level. Also, it may be entering pits, conduit trenches, and other underground spaces. Storm water drains probably discharge into the sea which would account for radioactivity found some distance from the shore.
With all of these pathways to the surface, from the spent fuel pool about four stories up in the secondary containment building, it might be difficult to figure out how to curtail the various pathways to pooling on site or flowing out to sea.
Logic would suggest that getting the installed cooling systems inside the reactors working again is the fast way to stop the uncontrolled flow of radioactive water outside them and around the site. TEPCO will have to find a way to determine the condition of the pumps and piping in order to decide if this is a feasible solution.
Dan – with all due respect, I think your background in DOE sponsored clean-up efforts has colored your view of the challenges and resources that face TEPCO. The impression that I get is that you believe that “millions” of gallons of water is an enormous amount that will present very difficult challenges for many years to come.
While I am not trying to minimize the difficulty, think about how many millions of gallons of water per day that an operational power plant the size of Fukushima is designed to handle as part of its normal operation.
I just happened to have been playing with some sea water flow numbers the other day because of the new EPA cooling water rules. Those rules apply to all facilities that use 2 million gallons of water per day or more. I wanted to find out the applicability in megawatts of thermal energy so I could get an idea for the size of generator. It turns out that a plant producing just 7 MWe needs at least 2 million gallons of cooling water per day.
Fukushima Daiichi had 6 units with a total of capacity of about 4400 MWe. At full power it would require at least 1250 million gallons of cooling water every day. What that means in this case is that before the tsunami, there were dozens of very large pumps and pipes on the site. There were also filters, ion exchangers, and holding tanks.
Presumably, some of that equipment is still functional and can be brought into use in a clean-up or cooling effort. As Jim Hopf pointed out, TEPCO will eventually move to a point where they are using some kind of closed cycle cooling and reusing the contaminated water as a coolant so that they stop producing more water that needs disposal.
They also have access to water borne vessels that can bring in large equipment and can handle large volumes of fluid. Tankers that travel the ocean are far cheaper per unit capacity than tankers that travel on highways. There are already news reports about Japan getting in touch with Russia to “borrow” some of the ships that Russia has used to clean up its decommissioned submarine fleet. As it turns out, Japan actually paid for at least one of the ships and gave it to Russia as part of the international effort to help out with that task.
I fully expect that the clean up will be difficult and expensive. I just do not think that it will be as difficult or expensive as your post implies.
There is no doubt in my mind that it will end up being a far more thorough clean up with far less impact on the surrounding area than BP’s rather superficial effort to clean up after the Deepwater Horizon’s fatal explosion and many months long spew of many millions of gallons of deadly chemicals into my beloved Gulf of Mexico.
As Robert pointed out – the aftermath should result in many thousands of additional nukes spread out all over the world who get the opportunity for hands on learning about the engineering and technology effort required to clean up after a major nuclear plant casualty.
While having an earthquake and tsunami wipe out 4400 MWe of emission free generating capacity is not a “good” thing, when mother nature dumps a huge load of lemons on you, it does not hurt to think about ways to turn them into lemonade, lemon pie, and lemon cake.
The difference is the radioactive water at Fukushima is not inside a reactor cooling circuit. A lot of it is in an uncontrolled state flowing down the sides of buildings into storm drains, into the sea, etc.
There is an interesting news report in the NYT for April 8 which notes hundreds of engineers from Toshiba / Westinghouse are working on the decommissioning issue. Also, the article notes that worker safety, an issue raised in this article, will be a key element of the D&D effort. That means tackling the problem of uncontrolled radioactive water. Here’s the URL for the NYT report.
Dan –
The difference is the radioactive water at Fukushima is not inside a reactor cooling circuit. A lot of it is in an uncontrolled state flowing down the sides of buildings into storm drains, into the sea, etc.
Agreed. The answer is to gather up that water and pump it into a place where it can be controlled. We also have to be realistic here – it is not as if the ocean and soil were not already “contaminated” with radioactive materials before the plant was destroyed by the earthquake and tsunami. There is no need to seek perfection – a reasonable standard of good enough would be to prevent harm to the general public and to ensure worker safety.
In any large industrial or construction effort, worker safety is ALWAYS a key element. It is never safe to be stupid about enforcing proper use of safety equipment, taking measures to prevent falls, and ensuring adequate training.
You think that the folks cleaning up after Deepwater Horizon had an easy time or were not exposed to materials that will have long term negative health effects? Heck, BP forced many of the people involved to work without proper protective equipment because they thought that the breathing gear and anti-contamination clothing would look bad on camera.
My experience is that the nuclear industry is under no such restrictions. TEPCO will protect its workers even if the images can be used to raise questions and concerns. I think that it is the responsibility of nuclear professionals to try to help people understand why we take precautions and why we express our own concerns BEFORE people get hurt.
My further comments on the issues raised by Rod Adams are on my blog Idaho Samizdat .
The Fukushima disaster brings to my mind q more primordial horror movie, Godzilla (Gojira) by the Japanese cineast Ishiro Honda, produced in 1954 and having the use of nuclear power in war freshly in mind. The Godzilla monster has been brought to life from the deep seabed by nuclear tests and the scenes of destruction and evacuation displayed do link much more directly to what has happened in Japan. There are sequences which show the use of a geiger-counter onto kids to see if they have been irradiated, there are scenes of evacuation of Tokyo, and it is the dilemma of the scientist to have made discoveries with far reaching consequences beyond his own scope that is the most central theme of this movie. The Japanese movie of 1954 has been Americanized and somehow politically smoothened… the original uncut version is today also available by TOHO and is a valuable exercise to view for anyone working in the nuclear business…..